The main line of the system is the former National Railroad extending from Laredo to the capital, a distance of eight hundred and thirty-nine miles, several hundred miles shorter than the Central. It passes through the important cities of Monterey, Saltillo, San Luis Potosi and Celaya. Originally constructed as a narrow gauge line, it has been changed to standard width throughout its entire length. The Mexican International Railroad, which enters Mexico at Eagle Pass and runs through Torreon to Durango with a branch to Monterey, has been added. The Interoceanic Railway, whose main line connects the capital with Vera Cruz, passing through Puebla, the third largest city in Mexico, is also now a part of this system. At the present time this line is narrow gauge, but preparations are now being made to widen it to standard gauge. Quite recently the government purchased the Hidalgo Railroad, which extends from the City of Mexico to Pachuca, State of Hidalgo. It is the intention of the government to extend this line immediately to Tampico, thus making a short and direct route to this port. In December, 1906, the government announced the purchase of the Mexican Central Railway, its only large competitor, and this road will be added to the system known as the National Lines. The reasons for this purchase were stated by Minister of Finance Limantour to be “the aggressive attitude assumed by certain great railway systems in the United States.” It was feared that the great railways of the United States would step in and absorb this important line, and saddle upon the people the trust evil. The Mexican Central is the largest railway system within the republic and owns more than three thousand five hundred miles of track. The main line extends from El Paso, Texas, to the capital in a southeasterly direction a distance of one thousand two hundred and twenty-four miles. This was the first road constructed to the United States border and received the largest subsidy of any line, amounting to $15,200 per mile. Construction work was begun in 1880 at both terminal points and rushed to completion so that through trains were running less than four years later. This made an average of nearly one mile for each working day. It traverses sections rich in agriculture and mineral resources and passes through many of the important cities. Among these are Chihuahua, Torreon, Zacatecas, Aguas Calientes, Leon, Irapuato, Celaya and Querétero. It reaches a population of several millions on the table lands.